BNNS502 pt 2 Exam Questions With 100%
Verified Answers
Functions of the nucleus - answer✔Control cellular structure, directs cellular activity, produces
ribosomes
How many pairs of chromosomes does the body have - answer✔23
2 chromosomes making up a chromosome pair are called - answer✔Homologous chromosomes
Allelels are - answer✔Alternative versions of a gene
Describe Homozygous vs Heterozygous alleles - answer✔Homozygous have identical info for a
trait where as heterozygous have different
What are the 2 types of cell division - answer✔Somatic and reproductive
What is the aim of somatic cell division - answer✔Replace dead or injured cells or add new ones
via mitosis and cytokinesis
What s the aim of reproductive cell division - answer✔Produce gamete haploid(23 single
chromosomes) cells via meiosis
What are the 3 stages of somatic cell division - answer✔- Interphase -Mitosis -Cytokinesis
What does Interphase involve - answer✔Doubling of genetic material, DNA unzips via enzyme
presence
What does Mitosis involve - answer✔4 stages in which nucleus/chromosomes divide
What occurs during cytokinesis - answer✔Division of cytoplasm to create 2 identical daughter
cells
Describe meiosis I and meiosis II - answer✔Meiosis I: 4 Stages that produce 2 genetically
different cells
Meiosis: Similar to mitosis (division of cytoplasm)
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What is the purpose of crossing over during meiosis I - answer✔Genetic variation because of the
exchange of genes homologous chromosomes
What is cancer - answer✔The result of uncontrolled or abnormal cell proliferation resulting in
excess tissue called a tumour
Carcinoma cancers arise from - answer✔Epithelial tissue
Leukaemia cancer arises from - answer✔WBC
Define inheritance - answer✔Passage of hereditary traits from one generation to another
Compare genotype to a phenotype - answer✔Genotype is the genetic makeup of an individual
and Phenotype is the physical characteristic determined by the genotype
Define Mutation - answer✔Permanent heritable change in a gene
Homozygous vs Heterozygous - answer✔Homozygous: Same alleles (PP,pp)
Heterozygous: Different alleles (Pp)
Are genetic disorders Dominant or recessive - answer✔Recessive and takes both parents to be
carriers
Autosomes vs sex chromosomes - answer✔Autosomes: Any chromosome that isn't a sex
chromosome
Sex chromosome: 23rd pair (XX or XY)
XX and XY code for - answer✔XX: Female
XY: Male
What does the X chromosome contain - answer✔Genes important for brain function, clottong
factor and cone pigments
Why are male sex linked traits more common - answer✔Because it always expressed because
there is no corresponding allele on Y chromosome, females must have 2 sexlinked recessive
alleles
What errors can occur during meiosis - answer✔Trisomy (2n+1) or monosomy (2n -1)
Down syndrome occurs when - answer✔There is an extra 21st chromosome
What is a teratogen - answer✔Any agent or influence that causes developmental defects in the
embryo ie chemicals, drugs, cigarettes, irradition