Unit notes and practice questions
Everything here is for unit 5 of the Grade 11 Biology textbook: what the chapter covers, the short notes, practice questions with their answers, and the lesson video where one exists.
The cards filed under this chapter on the Grade 11 Biology page. Open one at a time.
When you use it
Use when identifying the connecting functions of tendons and ligaments, or the distinct roles of bone cell types.
Watch out
Tendons connect muscle to bone, while ligaments connect bone to bone. Osteoblasts build new bone tissue, while osteoclasts break down and resorb bone tissue.
Drafted from Grade 11 Biology, pages 180-235, then checked twice before it went up
| Division | Components | Bone count |
|---|---|---|
| Axial skeleton | Skull (22), Ossicles (6), Hyoid (1), Rib cage (24), Sternum (1), Vertebral column (26) | |
| Appendicular skeleton | Shoulder girdles (4), Pelvis (2), Arms and forearms (6), Thighs and legs (8), Hands (54), Feet and ankles (52) | |
| Total adult skeleton | Axial skeleton + Appendicular skeleton |
When you use it
Use to recall the division of the adult human skeleton into axial and appendicular parts and their bone counts.
Watch out
Adults have 206 bones, but newborns have over 300 bones that fuse during maturation.
Drafted from Grade 11 Biology, pages 180-235, then checked twice before it went up
| Sexually transmitted infection | Pathogen type | Causative agent |
|---|---|---|
| Syphilis | Bacterium | Treponema pallidum |
| Gonorrhea | Bacterium | Neisseria gonorrhoeae |
| Chancroid | Bacterium | Haemophilus ducreyi |
| Genital herpes | Virus | Herpes simplex virus (HSV) |
| Genital warts | Virus | Human papillomavirus (HPV) |
| AIDS | Virus | Human immunodeficiency virus (HIV) |
| Trichomoniasis | Parasite | Trichomonas vaginalis |
When you use it
Use to match common sexually transmitted infections with their pathogen classification and specific causative organism.
Watch out
Condoms are the only contraceptive method that provides mechanical protection against sexually transmitted infections like HIV.
Drafted from Grade 11 Biology, pages 180-235, then checked twice before it went up
| Phase | Days | Major ovarian and hormonal event |
|---|---|---|
| Menstrual phase | 1-4 | Endometrium breaks down and sheds as menstrual flow |
| Follicular phase | 5-13 | FSH stimulates follicle growth, follicles secrete estrogen |
| Ovulation phase | 14 | LH surge triggers the release of a mature egg |
| Luteal phase | 15-28 | Corpus luteum forms and secretes progesterone to maintain endometrium |
When you use it
Use to determine the timeline, dominant hormones, and uterine changes across the four phases of the menstrual cycle.
Watch out
Ovulation is triggered by a surge in LH around day 14, not by FSH. Progesterone is highest during the luteal phase, not the follicular phase.
Drafted from Grade 11 Biology, pages 180-235, then checked twice before it went up
| Muscle type | Striation | Control | Location |
|---|---|---|---|
| Skeletal muscle | Striated | Voluntary | Attached to bones |
| Cardiac muscle | Striated | Involuntary | Heart wall (myocardium) |
| Smooth muscle | Non-striated | Involuntary | Hollow organs, blood vessels |
When you use it
Use to differentiate the structure, voluntary control, and location of the three human muscle types.
Watch out
Do not confuse cardiac muscle with smooth muscle. Cardiac muscle is involuntary like smooth muscle, but it is striated like skeletal muscle.
Drafted from Grade 11 Biology, pages 180-235, then checked twice before it went up
10 multiple-choice questions written against this chapter, each with its answer and the reason. Try one before you open the answer.
Question 1
Which type of muscle tissue is involuntary, non-striated, and found in the walls of hollow organs such as the stomach and intestine?
Answer: A Smooth muscle
Why
Smooth muscle cells are involuntary and non-striated. They line the walls of hollow organs like the stomach, intestine, and bladder.
Question 2
Which type of bone cells are directly responsible for the repair of bone fractures?
Answer: D Osteoprogenitor
Why
Osteoprogenitor cells play an important role in repairing bone fractures.
Question 3
Which male reproductive structure secretes fructose into semen to provide energy for sperm cells?
Answer: B Seminal vesicle
Why
The seminal vesicle secretes fructose into semen, which supplies energy to help sperm move.
Question 4
Which contraceptive method is the only one that helps prevent sexually transmitted infections (STIs)?
Answer: C Condom
Why
Condoms (both male and female) create a physical barrier that helps protect against sexually transmitted infections as well as pregnancy.
Question 5
During skeletal muscle contraction, what is the immediate effect of calcium flooding into the muscle cell from the sarcoplasmic reticulum?
Answer: B It binds with troponin, allowing actin and myosin to bind
Why
Calcium binds with troponin, which shifts tropomyosin out of the way and allows the actin and myosin cross bridges to bind and contract.
Question 6
How many total bones make up the human axial skeleton in an adult?
Answer: A 80
Why
The adult human skeleton consists of 206 bones, divided into the axial skeleton (80 bones) and the appendicular skeleton (126 bones).
Question 7
Around day 14 of the menstrual cycle, a surge in which hormone causes the ovarian follicle to rupture and release an egg?
Answer: B Luteinizing hormone (LH)
Why
A sudden surge in luteinizing hormone (LH) midway through the cycle triggers ovulation, the release of a mature egg from the ovary.
Question 8
Which structure is cut or blocked during a male sterilization procedure (vasectomy)?
Answer: C Vas deferens
Why
A vasectomy involves blocking or cutting each vas deferens tube to prevent sperm from entering the semen.
Question 9
A farmer in Gojjam lifts and holds a heavy bag of teff steady in his arms without changing muscle length. What type of muscle contraction is this?
Answer: C Isometric contraction
Why
An isometric contraction generates muscle tension without changing the length of the muscle.
Question 10
During the luteal phase, the corpus luteum produces high levels of progesterone and estrogen. What is the effect of these hormones on FSH and LH?
Answer: B They inhibit FSH and LH to prevent new follicles from developing
Why
High levels of progesterone and estrogen act as negative feedback, inhibiting the secretion of FSH and LH so that no new follicles mature during the luteal phase.
The app holds 12 questions on this unit, marked as you go. These are the first 10.
Unit 5 runs from page 180 to page 235 of the Ministry of Education edition.
Ministry of Education edition, English, 294 pages
Temari turns this chapter into timed practice and marks it as you go, with an AI tutor to explain anything that did not land.
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