Cell Division and Inheritance Flashcards
What is the function of the nucleus
Controls and regulates the activities of the cell, produces ribosomes and contains DNA
Define the term Alleles
Are alternative versions of genes
Define homozygous alleles
Have identical information for a trait
Define heterozygous alleles
Have different information for a trait
Name the two different types of cell division
Somatic cell division & reproductive cell division
Describe somatic cell division
Aims to replicate cells to replace dead or injured cells or add new cells. Occurs through mitosis & cytokinesis (you dont have sex with your toes, mytoesis)
Describe reproductive cell division
Aim is to produce the gamete cells (sperma nd oocyte). Occurs through meiosis (me=my sis=sex)
How many chromosomes are there in each somatic cell in somatic cell division? And where does cell division occur?
46 chromosomes and occurs through three main phases, Interphase, Mitosis and cytokinesis
How many chromosomes are there in each reproductive cell in cell reproductive cell division? and where does cell division occur?
23 chromosomes and occurs in the testes and ovaries
Explain how genetic variation occurs
When two homologous chromosomes partner up they exchange genetic material between non-sister chromatids
Define cancer
Cancer is the group of diseases that results from uncontrolled or abnormal cell proliferation
Define the term malignant tumour
Malignant tumours undergo metastases (the spread of cancerous cells to other parts of the body)
Define the term benign tumour
Benign tumours do not metastasise (they do not spread)
Name the type of cancer cell that arises from epithelial tissue
Carcinoma arises from epithelial tissue
Name the type of cancer cell that arises from melanocytes
Melanoma arises from melanocytes
Name the type of cancer cell that arises from lymphatic tissue
Lymphoma arises from lymphatic tissue
Name the type of cancer cell that arises from leukocytes
Leukemia arises from leukocytes
State three causes of cancer
Environmental agents like cigarette tar or UV light.
Viruses like HPV stimulate abnormal cell proliferation
Genes - abnormalities of genes that control and regulate cell division
Define inheritance
Inheritance is the passage of hereditary traits from one generation to another
Define genetics
Genetics is the branch of biology that deals with inheritance.
Define genotype
Genotype is the genetic makeup of an individual
E.g. Pp
Define phenotype
Phenotype is the physical characteristics determined by the genotype & the environment
E.g. brown hair, blue eyes
Define mutation
Mutation is a permanent, heritable change in a gene that causes it to have a different effect than it had previously.
Define autosomes
Autosomes are any chromosomes other than a sex chromosomes.