Bio Lecture Exam 3 Flashcards
The chromosome number is halved by __ and restored by __
meiosis; fertilization
the normal human karyotpe contains _ autosomes
22
at the conlcusion of s phase in mitosis, a diploid cell with 40 chromosomes will have _ chromosomes and _ sister chromatids
40; 80
what type of cell division do prokaryotes go through? explain your answer by comparing it to mitosis
Binary fission; mitosis only occurs in eukaryotes
generally which phase of the cell cycle varies the most in length depending on the type of cell
G1
Which of the following are characteristics of meiosis?
Haploid cells
Final cells have chromosome content n.
identify the stage of mitosis shown in image a
interphase
which process results in the production of offspring who are recombinant for two genes on the same chromosome
crossing over homo chromo
a cell entering the cell cycle with 32 chromosomes will produce two daughter cells each with
32 chromosomes
homologous chromosomes undergo recombination by exchanging segments during
prophase 1
pairs of alleles; are found at a particular _ on a pair of _
base; homo chromo
one type of cell cycle control signals is a
Cyclins
why is mitosis necessary
growth; replace old or damaged cells
if an intestinal cell ina grasshopper contains 24 chromosomes, a grasshopper sperm cell after undergoing meiosis would contain _ chromosomes
12
when an indnividual has two different alleles for a given gene they are _ for that gene
heterozygous
the daughter cells produced by meiosis are _
haploid
chromosomes are in a condensed form at which stages of the cell cycle
metaphase
nondisjunction during meiosis I might result in
down syndrome; abnormal gametes that contain two members of the affected chromosome or none at all
the separation of duplicated chromosomes into two new nuclei is known as
mitosis
identify the stage of mitosis in panel E
metaphase
your father has type b blood, and your mother has type o blood. you learn that you also have blood type O. What does this tell you
Your father’s genotype is IBi and your mother’s genotype is ii.
the main difference between bacterial cell division and eukaryotic cell division is that
Bacterial DNA replication and chromosome segregation are concerted processes but in eukaryotes they are separated in time.
A parent has a genotype of RrYy. What is the probability of having a gamete with the RY genotype?
1/4
following the completion of meiosis in animals, males produce _ sperm cells and females produce _ eggs
4; 1
which statement best describes the difference between cell division in plant and animal cells
In animal cells cytoplasmic division is accomplished by “pinching in” of the cell membrane, while in plant cells a cell plate is synthesized.
which sequence of the cell cycle is correct
G1 → S → G2 → M
if you examine your karyotype and see 23 pairs of homologous chromosomes, explain what the homologues are
pairs of chromosomes that possess similar genetic information
who was given the title of father of genetics
Gregor Mendel
polygenic inheritance is often modified by
envrionment
The ability of an individual heterozygous for two different genes to produce its four gamete types in equal numbers reflects Mendel’s Law(s) of…
Segregation and Independent Assortment
after fertilization the newly formed zyogte Grows by
mitosis
the cells in the human body that are produced by mitosis are
somatic
when pairs of homologous chromosomes come together to form tetrads what occurs
synapsis
sexual reproduction has an advantage over asexual reproduction by
genetic variability
once human nerve cells become mature they normally exit the cell cycle and remain in
G0 phase
genetic variability in meiosis results from
recombination of homologous chromosomes, independent assortment of chromosomes, and random joining of male and female gametes
what is the key difference between incomplete dominance and codominance
codom: no allele can block the expression of the other allele
incomp dom: a dom allele doesn’t completely block the effects of a recessive allele
in snapdragons, the red allele cr is incompletely dominant over the whtie allele cw. if you cross a pink snapdragon with a white snapdragon
0%
which type of aneuploidy is less detrimental? aneuploidies on the sex chromosomes or the autosomes. Why?
Sex; process of X-inactivation
which disorder is an example of pleiotropy
phenylketonuria
explain what the term polygenic inheritance means
inheritance of a trait due to more than one gene
what would not happen in anaphase 1
splitting of centromere
which statement describes a similarity between meiosis and mitosis
crossing over
Your mother has albinism, which is a recessive trait. You learn that your spouse’s mother also has albinism. Neither you nor your spouse have albinism. What are the odds that your first child will have albinism?
1/4
identify the stage of mitosis shown in panel B
Anaphase
