17 Of these which represents a heterozygote a aa b Aa c AA d

17. Of these, which represents a heterozygote?
a. aa
b. Aa
c. AA
d. both a. and c.

18. Active transport across a cell membrane is
a. moving a molecule from lower to higher concentration
b. moving a molecule from higher to lower concentration
c. moving a molecule from outside the cell to inside the cell
d. a method by which cells get rid of waste products

19. All of the following are true about the cell membrane except _____.
a. They are mainly composed of lipids and proteins
b. All polar molecules pass freely, directly through the membrane
c. They are selectively permeable.
d. They have a lipid bilayer

20. Which cellular process produces the most ATP?
a. Photosynthesis
b. aerobic respiration
c. meiosis
d. anaerobic respiration

21. A plant can regulate the amount of water in its cells by
a. moving to a more aqueous environment
b. increasing the amount of solute in the cytoplasm
c. reducing its rate of respiration
d. drinking a tall glass of refreshing rain water

22. Eye color is represented by the alleles AaBBCc. This is an example of ______.
a. complete dominant inheritance
b. heterozygote advantage
c. sex-linked inheritance
d. polygenic inheritance

23. During amniocentesis the baby\'s cells are obtained from the ____.
a. fluid around the embryo
b. placenta
c. uterine wall
d. developing embryo

Solution

17.The word \'hetero\' itself means different and zygote means an eukaryotic cell formed by a fertilization event between two gametes.The answer is (b) as there are two different alleles A and a.

18.a)moving a molecule from lower to higher concentration.

When the movement of molecules across acell membrane from a region of their lower concentration to aregion of their higher concentration in the direction against some gradient or the other obstructing factor this is called active transport.

19.(b)All polar molecules pass freely,directly through the membrane.

The cell membrane allows only selective molecules to pass,which are required to the membrane.

20.(aerobic respiration)

Beccause the majority of ATP is produced in the mitochondria during aerobic respiration.

21.(b)increasing the amount of solute in the cytoplasm

because the stomata opens up and aquire the water and stores it.The amount of water in the cells get regulated by increasing the amount of solute in the cytoplasm.

22.(d)Polygenic inheritence

As the capital letters are indicated as dominant.Here A has appeared once,B has appeared twice and C has appeared once ,which becomes a dominant allele as there are less recessive characters.

23.(a)Fluid around the embryo

Which has cell of the baby and help in diagnosing,whether the baby is a male or female by chromosomal detection.