genes

Question 1

Allele

Answer 1

Various and specific forms of a gene that vary by one or two bases

Question 2

Relationship between DNA, chromosomes, and genes

Answer 2

DNA is a molecule that contains genetic material responsible for the function of an organism. Chromosomes are long DNA molecules that contain many genes. Genes are short stretches of DNA that code for one characteristic.

Question 3

Genome

Answer 3

The entire genetic material of an organism

Question 4

Relationship between alleles and mutations

Answer 4

Mutations arise from daughter cells containing DNA that differs from the parental cell’s DNA. New alleles are created by mutation.

Question 5

Sickle-cell anemia

Answer 5

Sickle cell anemia is caused by one single-base substitution mutation (GLU to VAL). The new shape of the sickled red blood cell causes it to get stuck and clog blood vessels.

Question 6

Homologous pair

Answer 6

2 versions of the same chromosome (one from paternal & one form maternal)

Question 7

Haploid

Answer 7

1 sister chromatid (half of 1 homologous chromosome)

Question 8

Diploid

Answer 8

2 sister chromatids together (1 homologous chromosome)

Question 9

Gamete

Answer 9

Sex cells (sperm & ova)

Question 10

Karyogram

Answer 10

Shows the chromosomes of an organism in homologous pairs of decreasing length

Question 11

Nondisjunction

Answer 11

Occurs when homologous pairs or sister chromatids fail to separate (during anaphase I/II of meiosis)

Question 12

Locus

Answer 12

Exact position of a gene on a chromosome

Question 13

Asexual reproduction includes:

Answer 13

Binary fission and mitosis

Question 14

Sexual reproduction includes:

Answer 14

Meiosis

Question 15

Sister chromatids

Answer 15

Identical and joined at the centromere

Question 16

Tetrad or bivalent

Answer 16

4 homologous chromatids or 2 homologous chromosomes

Question 17

Synapsis

Answer 17

Process where homologous pairs of replicated chromosomes align closely during prophase I

Question 18

Recombinant gametes

Answer 18

Gametes containing new combos of alleles, different from the 2 parents

Question 19

Meiosis I vs meiosis II

Answer 19

Paired chromosomess separate in meiosis I. Unpaired chromosomes separate in meiosis II.

Question 20

Random orientation

Answer 20

The behaviour of alleles of unlinked genes as a result of gamete production

Question 21

Crossing over

Answer 21

NON-SISTER HOMOLOGOUS CHROMATIDS are exchanged by breaking of COVALENT bonds in BACKBONE of DNA strands causing helices to SWITCH.

Question 22

Individual assortment

Answer 22

The allele inherited for one gene does not influence which allele is inherited for a different gene.

Question 23

Homozygous

Answer 23

Having the same alleles of a gene (YY/yy)

Question 24

Heterozygous

Answer 24

Having different alleles of a gene (Yy)

Question 25

Zygote

Answer 25

Fertilized egg cell

Question 26

Chiasmata

Answer 26

Where crossing-over occurs

Question 27

Outline first part of MEIOSIS (prophase I, metaphase I, anaphase I, and telophase I)

Answer 27

PROPHASE I: Nuclear membrane dissolves, spindle fibers start to form crossing over. METAPHASE I: Paired chromosomes line up at equator of cell, a spindle fiber attaches to each pair. ANAPHASE I: Spindle fibers pull the paired chromosomes apart. TELOPHASE I: Chromosomes arrive at opposite poles of the cell and nuclear membrane may reform.

Question 28

Outline second part of MEIOSIS (prophase II, metaphase II, anaphase II, telophase II)

Answer 28

PROPHASE II: Nuclear envelope breaks, spindle fibers form between centrosomes. METAPHASE II: Unpaired chromosomes line up at equator of the cell. ANAPHASE II: Unpaired chromosomes separate and are pulled to opposite poles of the cell. TELOPHASE II: Nuclear membranes begin to reform around new chromosomes, chromosomes decondense.