BIOH111 SESSION 1 HOMEOSTASIS, CELL ORGANISATION &
FUNCTION OF ORGANELLES EXAM QUESTIONS AND ANSWERS
WITH COMPLETE SOLUTIONS GRADED A++ LATEST UPDATE
Levels of organisation
1. Chemical
2. Cellular
3. Tissue
4. Organ
5. System
The chemical level
atoms (units of matter participating in chemical reactions)
& molecules (two or more atoms joined together)
Cells
Basic structural and functional units of an organism
Tissues
groups of similarly specialised cells and substances surrounding them
Organs
structures of definite form composed of two or more different tissues
Systems
related organs that have a common function:
e.g. integumentary, skeletal, muscular, nervous, endocrine
, Homeostasis
State of balance/equilibrium that the body constantly tries to achieve
Negative feedback loop
Nervous system detects changes and sends nerve impulses to counteract the change.
e.g. detects warm weather, induces sweating to cool the body
Positive feedback loop
The body detects changes and sends signals to continue the changes.
e.g. childbirth/labour
Cytoplasm
cellular content between plasma membrane and the nucleus
Endoplasmic Reticulum (ER)
Site of protein & lipid synthesis
flattened membranes forming flattened sacs/tubules called cisterns.
Two organelles, one with Ribosomes and one without Ribosomes
Ribosomes
Site of protein synthesis
Free in the cytosol or attached to the Rough ER
Golgi Complex
flattened membraneous sacs (cisters) referred to as cis, medial, and trans.
Sorts and modifies newly synthesized proteins, prepares for packaging and delivery
Mitochondria
double membrane bound organelle with inner membrane arranged in folds.
Site of cellular ATP synthesis
FUNCTION OF ORGANELLES EXAM QUESTIONS AND ANSWERS
WITH COMPLETE SOLUTIONS GRADED A++ LATEST UPDATE
Levels of organisation
1. Chemical
2. Cellular
3. Tissue
4. Organ
5. System
The chemical level
atoms (units of matter participating in chemical reactions)
& molecules (two or more atoms joined together)
Cells
Basic structural and functional units of an organism
Tissues
groups of similarly specialised cells and substances surrounding them
Organs
structures of definite form composed of two or more different tissues
Systems
related organs that have a common function:
e.g. integumentary, skeletal, muscular, nervous, endocrine
, Homeostasis
State of balance/equilibrium that the body constantly tries to achieve
Negative feedback loop
Nervous system detects changes and sends nerve impulses to counteract the change.
e.g. detects warm weather, induces sweating to cool the body
Positive feedback loop
The body detects changes and sends signals to continue the changes.
e.g. childbirth/labour
Cytoplasm
cellular content between plasma membrane and the nucleus
Endoplasmic Reticulum (ER)
Site of protein & lipid synthesis
flattened membranes forming flattened sacs/tubules called cisterns.
Two organelles, one with Ribosomes and one without Ribosomes
Ribosomes
Site of protein synthesis
Free in the cytosol or attached to the Rough ER
Golgi Complex
flattened membraneous sacs (cisters) referred to as cis, medial, and trans.
Sorts and modifies newly synthesized proteins, prepares for packaging and delivery
Mitochondria
double membrane bound organelle with inner membrane arranged in folds.
Site of cellular ATP synthesis
