Section 3b Inheritance

Question 1

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Answer 1

Nucleus of a cell contains chromosomes. Chromosomes contain genes which code for a specific protein.

Question 2

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Answer 2

In a DNA strand, there are phosphate sugar backbones (double stranded) which are attached to nitrogenous bases. Adenine attaches to Thymine, Guanine attaches to Cytosine. These base pairs have complimentary shapes.

Question 3

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Answer 3

Alleles - Different version of the same gene.

Question 4

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Answer 4

Dominant - Dominant allele is the one that will be made Recessive - Recessive allele is the one that will be masked by the dominant and not be made Codominance - Both alleles can be dominant Homozygous - 2 copies of the same allele Heterozygous - 2 different alleles at the locus Phenotype - Traits that are expressed

Genotype - Tells you the genes they have

Question 5

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Answer 5

Question 6

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Answer 6

Question 7

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Answer 7

The sex of a person is controlled by two pairs of chromosomes, XX female, XY male.

Question 8

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Answer 8

Mitosis:

A diploid cell divides by mitosis. It has 46 pairs of chromosomes.

• Chromosomes makes a copy of itself (DNA replication).
• Line up at center.
• Pulled apart by spindle fibers.
• Cell divides into two.

2 diploid cells are formed, with identical chromosomes.

Mitosis occurs at growth, repair, cloning and asexual reproduction.

Question 9

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Answer 9

Meiosis

A diploid cell contains 46 pairs of chromosomes.

• Chromosomes makes copies of itself
• Line up at center
• Pulled apart by spindle fibers
• Divides into two
• Pulled apart by spindle fibers (at center again)
• Divides into two once more

4 Haploid cells/sex cells/gametes are formed, which only contain 23 pairs of chromosomes. These gametes are genetically different

Question 10

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Answer 10

Since the gametes of the parents vary genetically, the offspring will have different genotypes, which is why the offspring is genetically different from the parents.