A master of biology must be a master

Of course, swap refers to the exchange of homologous fragments on homologous chromosomes, and there are homologous fragments on xy chromosomes, but high school doesn't say much, and the last question in the 2007 college entrance examination science paper national paper is this problem, so male gametes are interchangeable, but high school doesn't say much.

Male gametes do not contain homologous chromosomes, and cross-swapping can only occur between homologous chromosomes, so male gametes cannot be cross-swapped. Your teacher's point is correct.

The Y chromosome and the X chromosome are interchangeable and they have homologous segments.

Can male gametes be cross-swapped?

It depends on the species, if it's a fruit fly, it's not good, and many other creatures can.

Your teacher is talking about fruit flies.

A lot of middle school biology uses it as an example.

You're a good learner. Hehe.

According to high school studies, the Y chromosome has only one homologous segment that is identical to X, and it is not possible to interchange.

I don't understand why your teacher said that, I think it may be that you misunderstood, the teacher said that the Y chromosome and the X chromosome are not interchangeable.

First of all, it is necessary to understand the conditions and characteristics of photosynthesis and cellular respiration, that is, photosynthesis must be carried out under light, and cellular respiration can be carried out with and without light. In order to rule out interference, the measurement of cellular respiration (aerobic) should be carried out in dark conditions, and photosynthesis must be measured under light, but since respiration is also taking place at this time, the net photosynthesis after respiration is subtracted! Total photosynthesis, respiration, net photosynthesis.

The solid line in the figure represents respiration and the dotted line represents net photosynthesis, so it is not difficult to see that the corresponding points of the two curves will always have equal values after superposition (i.e., the photosynthetic intensity may be the same at different temperatures).

The assay of cellular respiration (aerobic) should be performed in dark conditions, b correct!

At 35, the net photosynthesis is the largest, the most suitable for growth, c is correct!

At 40, the net photosynthesis is equal to respiration, that is, the total photosynthesis is greater than the respiration (the net photosynthesis is not 0), and the green algae will definitely grow, d is correct!

This question is extremely loose as a multiple-choice question! There are two correct answers!

Respiration at 40 is higher than photosynthesis, which means that the green algae cannot accumulate enough energy to survive, and of course cannot grow

Obviously, A is correct The light intensity must be the same at each temperature, which is the requirement of biological experiments: there is only a single variable, B is the correct determination of respiration must be measured in the dark, because at this time there is only respiration without photosynthesis, and there is both photosynthesis and respiration under light, which cannot be measured, and option C is also correct, the net photosynthetic rate is the largest at 35 (the dotted line in the figure refers to the net photosynthetic rate, the solid line represents the respiration rate, and the sum of the two represents the photosynthetic rate), so it is most beneficial for the growth of green algae, At this time, the accumulation of organic matter in the same time is the most, d is wrong, it can be seen from the figure that the net photosynthetic rate at 40 is 0 (note: photosynthetic rate - respiration rate = net photosynthetic rate), that is, organic matter can accumulate at this time, so green algae can grow at this temperature.

The temperature at which it cannot grow is about 42 or more after the intersection of the dotted line and the horizontal axis.

It's okay to explain, if you have any questions, you can continue to ask.

a For any experiment, there must be only one variable.

b Green plants can photosynthesize in the presence of light, and photosynthesis produces oxygen, so oxygen consumption should be measured in dark conditions.

c As can be seen from the figure, the distance between oxygen consumption and oxygen production is the largest, which means that organic matter accumulates the most, so it is the most suitable for its growth.

d The oxygen production and oxygen consumption in the figure are equal, which means that there is no accumulation of organic matter and no negative accumulation, which is equivalent to the static of the plant, not that it cannot grow. After 40 degrees, oxygen consumption and oxygen production, the organic matter in the plant will accumulate negatively, and the plant will "shrink", and if it is in this state for a long time, the plant will eventually die and wither.

So it's d

aFalse, the light intensity needs to be the same under each temperature condition.

b Correct, no need to explain, creature master?

c is correct, because the interval between the middle is the largest, and the vertices grow in a curve, and the respiration grows in a straight line, so 35 degrees is optimal.

d is correct, because at 40 degrees the breath photosynthetic dynamic equilibrium, but this is the situation during the day, there is no light at night, and the green algae can be miserable... So choose A

The answer should be D. The rate of oxygen production under light indicates the net photosynthetic rate, and the rate of oxygen consumption represents the rate of respiration. Total photosynthetic rate = net photosynthetic rate + respiration rate.

At 40 degrees, the two curves intersect, the net photosynthetic rate = respiration rate, and the total photosynthetic rate is 2 times the respiration rate. Photosynthetic rate Respiration rate, the plant can grow normally. d error.

I think the question should be selected d, I don't know if the answer is right, analyze my thoughts, I think the most important thing to examine is the understanding of the word "oxygen production rate", I think oxygen production is already the total oxygen production minus the amount of oxygen released after oxygen consumption, so at this point at 40 degrees Celsius can only explain the amount of oxygen released by the seaweed = oxygen consumption, indicating that it can still grow, (for example, if the seaweed produces a total of 40ml of oxygen per hour at 40 degrees Celsius, Then consumed 20ml, then its oxygen release at this time is equal to the oxygen consumption, which is the intersection in the figure), I don't know if you understand this, I hope it can help you!

d At 40 degrees, the net photosynthetic rate is not zero, the dotted line represents the net photosynthetic rate, the net photosynthetic rate = total photosynthesis-respiration, as long as the net photosynthesis is not zero, there is an accumulation of organic matter, and the plant will grow.

Pick D. It has been stated in the question stem that it is "measured oxygen production", that is, the curve in the figure is the sum of net light, and its value is greater than 0 at 40 degrees, indicating that there is an accumulation of organic matter and can grow.

d The rate of oxygen production measured under light is the net amount, i.e., the total amount - respiration, 40 The green algae can grow.

a. False, breathing is carried out in the absence of light.

1. Parent: aa aa

Gametes: a a a a

Youngsters: aa aa aa aa

If two traits appear in the offspring of the parental cross with relative traits, then one of the parents must be heterozygous, and the progeny must have two traits with the same probability of 50%, so it is impossible to judge which trait is dominant or recessive.

2. Parent: AA AA

Gametes: a a a a

Youngsters: aa aa aa aa

After inbreeding, the offspring will be separated from each other, and the parents will definitely be heterozygous. Then the traits it exhibits should also be dominant traits. (Mendel's Law).

1.That is, if these two traits are specific in the offspring produced by the parental hybridization corresponding to the traits, then it is impossible to judge the explicit recessiveness of the traits. For example:

If one is a mute parent and a non-mute parent, and there are mutes and non-mute offspring, then it is impossible to determine whether the gene that controls the mute is dominant or recessive. Because of the dominant recessive inheritance, the phenotype of the offspring is likely to be like this.

2.That is, after inbreeding, its offspring show two corresponding traits, so its parents are dominant traits. For example:

The parents are red-eyed, and their inbred offspring have both red-eyed and white-eyed. Then the red eye is dominant to the white eye. Assumptions:

If the gene that controls red eye is A, and the gene that controls white eye is A, then A is dominant to A.

I guess you're genetic, let me explain it this way.

1. If the parents with relative traits are crossed, and the child represents the two traits, the parental genotype of the relative trait is AA and AA crossing, and the other genotypes do not match, so it is impossible to judge which parent of the relative trait is dominant (AA) and which is recessive (AA).

2. If trait separation occurs in the offspring after self-breeding, the parental genotype can only be AA, and trait separation cannot occur in other genotypes self-breeding, and the parental genotype is AA, so the parental trait is a dominant trait.

Hope the explanation helps you.

Methods for judging dominant recessiveness If a parent with a relative trait is crossed and the offspring exhibits a trait, then the trait is dominant.

Something out of nothing is implicit, and something out of nothing is explicit.

Note: Answers can be derived from .

2. If the parental trait is recessive trait (aa), do you think he can have trait separation?

There are two traits that cannot be judged.