BIOS 256 WEEK 8 FINAL EXAM WITH ANSWERS
GUARANTEED PASS (FALL-SPRING SESSION)
sperm - ANSWER: - male sex cells
oocytes - ANSWER: - also called eggs
- female sex cell
sex cell production - ANSWER: - sex cells have 1 set of genetic instructions found on
23 chromosomes, compared to 2 sets of 46 chromosomes in other body cells
- when the sperm and egg unite at fertilization, the genetic information carried on 46
chromosomes is restored
- sex cells are produced by a special type of cell division called meiosis
meiosis - ANSWER: - includes 2 successive divisions, called the first (meiosis I) and
second (meiosis II) meiotic divisions
- prior to meiosis, each chromosomes replicates and contains 2 DNA strands, called
chromatids, connected by a centromere
somatic cells - ANSWER: - diploid cells
- are your body cells
- they undergo mitosis when they need to divide
two cell types - ANSWER: - somatic cells
- germ cells
germ cells - ANSWER: - haploid cells
- are your reproductive cells also referred to as gametes
> male gametes are called sperm cells
> female gametes are called egg cells
two types of chromosomes - ANSWER: - the chromosome types are divided into two
categories, autosomes and sex chromosome
- XX = female
- XY = male
autosomes - ANSWER: - are structures that contain the hereditary information
- they do not contain information related to reproduction and sex determination
- they are identical in both sexes, i.e., male and female species of humans
- there are 46 (2n) chromosomes in humans
- of these 46 chromosomes, there are 44 pairs of autosomes and contain information
related to the phenotypic characters
> physical features
, allosomes/heterosomes - ANSWER: - are sex chromosomes that are different from
autosomes in form, behavior and size
- there are two allosomes in humans
> the X chromosomes are present in the ovum and either the X or Y chromosome
can be present in the sperm
- these chromosomes help in determination of sex of the progeny
- if the offspring receives X chromosome from the mother as well as father, it results
in a female child (XX)
- if the offspring receives one X and one Y chromosome from the parents, it results in
a male child (XY)
- in simple words, it is the donation of X or Y chromosome by the father that helps
the determination of the sex of the child
ploidy - ANSWER: - in genetic, the number of chromosomes occurring in the nucleus
of a cell
- in normal somatic (body) cells, the chromosomes exist in pairs
> the condition is called diploidy
- during meiosis the cell produces gametes, or germ cells, each containing half the
normal or somatic number of chromosomes
> this condition is called haploidy
> when two germ cells (e.g., egg and sperm) unite, the diploid condition is restored
diploid - ANSWER: - cells have two copies of each chromosome: one copy from the
mother and one from the father
haploid - ANSWER: - cells have only one copy of each chromosome
meiosis I - ANSWER: - separates homologous (the same, genes for gene) pairs of
chromosomes
> they may not be identical, because a gene may have variants
> results in 2 haploid cells, which contain 1 set of chromosomes; these
chromosomes are still replicated, containing 2 chromatids
meiosis II - ANSWER: - separates the sister chromatids, producing cells that are still
haploid, but whose chromosomes now have 1 chromatid
> end result: 4 haploid cell in males, 1 haploid cell in females
there are 4 phases in meiosis I - ANSWER: - prophase I
- metaphase I
- anaphase I
- telophase I
prophase I - ANSWER: - involves synapsis: pairing of homologous chromosomes
- crossover occurs: exchange of genetic material between homologous
chromosomes, to produce chromosomes with genetic information from both
parents
GUARANTEED PASS (FALL-SPRING SESSION)
sperm - ANSWER: - male sex cells
oocytes - ANSWER: - also called eggs
- female sex cell
sex cell production - ANSWER: - sex cells have 1 set of genetic instructions found on
23 chromosomes, compared to 2 sets of 46 chromosomes in other body cells
- when the sperm and egg unite at fertilization, the genetic information carried on 46
chromosomes is restored
- sex cells are produced by a special type of cell division called meiosis
meiosis - ANSWER: - includes 2 successive divisions, called the first (meiosis I) and
second (meiosis II) meiotic divisions
- prior to meiosis, each chromosomes replicates and contains 2 DNA strands, called
chromatids, connected by a centromere
somatic cells - ANSWER: - diploid cells
- are your body cells
- they undergo mitosis when they need to divide
two cell types - ANSWER: - somatic cells
- germ cells
germ cells - ANSWER: - haploid cells
- are your reproductive cells also referred to as gametes
> male gametes are called sperm cells
> female gametes are called egg cells
two types of chromosomes - ANSWER: - the chromosome types are divided into two
categories, autosomes and sex chromosome
- XX = female
- XY = male
autosomes - ANSWER: - are structures that contain the hereditary information
- they do not contain information related to reproduction and sex determination
- they are identical in both sexes, i.e., male and female species of humans
- there are 46 (2n) chromosomes in humans
- of these 46 chromosomes, there are 44 pairs of autosomes and contain information
related to the phenotypic characters
> physical features
, allosomes/heterosomes - ANSWER: - are sex chromosomes that are different from
autosomes in form, behavior and size
- there are two allosomes in humans
> the X chromosomes are present in the ovum and either the X or Y chromosome
can be present in the sperm
- these chromosomes help in determination of sex of the progeny
- if the offspring receives X chromosome from the mother as well as father, it results
in a female child (XX)
- if the offspring receives one X and one Y chromosome from the parents, it results in
a male child (XY)
- in simple words, it is the donation of X or Y chromosome by the father that helps
the determination of the sex of the child
ploidy - ANSWER: - in genetic, the number of chromosomes occurring in the nucleus
of a cell
- in normal somatic (body) cells, the chromosomes exist in pairs
> the condition is called diploidy
- during meiosis the cell produces gametes, or germ cells, each containing half the
normal or somatic number of chromosomes
> this condition is called haploidy
> when two germ cells (e.g., egg and sperm) unite, the diploid condition is restored
diploid - ANSWER: - cells have two copies of each chromosome: one copy from the
mother and one from the father
haploid - ANSWER: - cells have only one copy of each chromosome
meiosis I - ANSWER: - separates homologous (the same, genes for gene) pairs of
chromosomes
> they may not be identical, because a gene may have variants
> results in 2 haploid cells, which contain 1 set of chromosomes; these
chromosomes are still replicated, containing 2 chromatids
meiosis II - ANSWER: - separates the sister chromatids, producing cells that are still
haploid, but whose chromosomes now have 1 chromatid
> end result: 4 haploid cell in males, 1 haploid cell in females
there are 4 phases in meiosis I - ANSWER: - prophase I
- metaphase I
- anaphase I
- telophase I
prophase I - ANSWER: - involves synapsis: pairing of homologous chromosomes
- crossover occurs: exchange of genetic material between homologous
chromosomes, to produce chromosomes with genetic information from both
parents
