Lecture 18 Study Guide

Question 1

Define the following:
genes
somatic cells
gametes
gene locus
genome 
life cycle
karyotype
haploid
diploid
germ cells
autosomes
sex chromosomes

Answer 1

genes: inheritable from parent chromosomes
somatic cells: body cells
gametes: sex cells
gene locus: where a gene is located on a chromosome
genome: genetic material 
life cycle: meiosis, fertilization, mitosis
karyotype: shows chromosomes in a cell
haploid: half the cells
diploid: 2n
germ cells: gives rise to gametes
autosomes: all cells
sex chromosomes: determines gender

Question 2

How to the offspring produced by asexual reproduction differ from those of sexual reproduction?

Answer 2

they have 100% of their parent’s genes while sexual reproduction offspring have 50% of each parents genes

Question 3

State the total number of chromosomes present in a single human diploid cell.
State the number of chromosome pairs in single human diploid cell.
State the total number of chromosomes in a human haploid cell (gamete)
State the number of chromosome pairs in a human haploid cell (gamete
)Identify structures a. and b. on the line drawing of a chromosome in prophase shown to the right.

Answer 3

46
23
23
none
centromere and sister chromatids

Question 4

Distinguish between autosomes and sex chromosomes. How is gender determined? How is gender inherited?

Answer 4

autosomes are all chromosomes except sex chromosomes

gender is determined by whether an offspring has xx (one from mom and one from dad) or xy (y from dad)

Question 5

List three mechanisms that allow human complexity to be coded for by only 21,000 genes.

Answer 5

random alignment
crossing over
random fertilization

Question 6

Define pseudogene:
Define intergenic DNA:
Define repetitive DNA:

Answer 6

pseudogene: similar to normal genes but nonfunctional
intergenic: a stretch of DNA sequences located between genes
repetitive DNA: patterns of DNA