Cells to Organisms Flashcards
What are the 6 essential characteristics of life?
organisation, metabolism, responsiveness, growth, development, reproduction
What are the 3 defining characteristics of vertebrates?
vetertebral column, 2 semi-circular canals, numerous soft tissue specialisation
What is metabolism the ability to do?
break down food and create energy
What is metabolism necessary for?
vital functions
What sort of cells are most human cells?
eukaryotic
Name the 8 key structures of a human cell
nucleus, endoplasmic reticulum, golgi apperatus, mitochondria, cilia, cytoplasm, cell membrane, micro villi
What is the function of the nucleus?
contains DNA, directs cell activity
What is the function of endoplasmic reticulum?
rough ER involved in protein synthesis and smooth ER involved in lipid and carbohydrate manufacture
What is the function of the golgi apperatus?
modifies, packages and distributes proteins for internal use and secretion
What is the function of mitochondria?
site of intercellular energy production in the form of ATP, used for aerobic respiration
what is the function of cilia?
move material over the cells surface (e.g. up the trachea from the lungs)
What is the function of cytoplasm?
fluid inside the cell, catalyses decomposition and synthesis reactions. includes the cytoskeleton (provides cellular support), micro tubules and inclusions
What is the function of the cell membrane?
phospholipid bylayer, separates ECF from ICF, provides attachment between cells
What is the function of micro villi?
increase the surface area of the cell
What does mitosis produce?
an identical daughter cell
How much cell time is spent in interphase?
90%
What is happening in the cell during interphase?
cell is between cell division, phase of routine metabolism followed by DNA synthesis, followed by preparation for division
How much of the time is the cell undergoing cell division?
10%
What are the 5 phases of mitosis?
interphase, prophase, metaphase, anaphase, telophase
How may cells worth of DNA is there at the end of interphase?
2 cells worth
What happens during prophase?
DNA condenses into chromosomes
What happens during metaphase?
chromosomes line up at the cell centre
What happens during anaphase?
cells start to seperate
What happens during telophase?
new nuclear envelopes form around the 2 sets of chromosomes
How many chromosomes are there in a diploid cell?
46 or 23 pairs
What is a karyotype?
the display of 23 chromosomal pairs of a somatic cell during metaphase of mitosis
How many chromosome pairs are there in the karyotype?
22 autosomal and 1 sex
What happens during meiosis?
chromosome number is halved creating haploid cells
What does the parent cell undergo before meiosis?
DNA replication and 2 cycles of nuclear division
What happens during meiosis 1?
chromosomes duplicate during interphase and homologous chromosomes can exchange genetic information in a process called synapsis/crossing over
What does the exchange of genetic information by homologous chromosomes lead to?
normal genetic variation
What happens during meiosis 2?
daughter cells divide again, split from their sister chromatids to form 4 haploid gametes
how many chromosomes are there in a haploid gamete?
23
What is resolving power?
the ability to see differences between objects
How does the resolution of a light microscope and an electron microscope compare?
light microscope has limited resolving power, electron microscope has high resolving power and magnification
Why do dyes show structures under a light microscope?
cytoplasmic proteins are acidophillic and therefore absorb an acid dye, nuclei are basophillic and therefore absorb a basic dye
What is a commonly used dye?
Haematoxillin and eosin
